Fig 7.

Qualitative mating and halo assays to measure a-factor activity. Mating and halo assays are shown for a wild-type (WT) strain and the indicated mutants. For the mating assay, MATa cells are patched onto a lawn of MATa mating tester cells spread onto SD medium, on which only diploids can grow. For halo assays, the MATa cells are patched onto a lawn of a MATa sst2 halo tester cells on rich medium. The extent of growth inhibition of the underlying lawn reflects the amount of a-factor present and is called an a-factor halo. The assays are discussed in the text.